Document EP 2 266 166 describes an antenna with a cavity, with the cavity delimited by a partially reflecting flat surface facing a totally reflecting flat surface.
The partially reflecting flat surface is constituted of an array of resonant cells forming micro-antennas. The phase of the micro-antennas is controlled by using varactor diodes. It is as such possible to control the de-aiming of the antenna and its emitting frequency.
However, due to the dimensions of the partially and totally reflecting flat surfaces, this antenna cannot be integrated in all systems, in particular into the fairings of vehicles.